Electro-optic relaxation measurements (transient electric birefringnece and dichroism) are being made on muscle proteins and nucleic acids. The muscle studies are aimed at elucidating the structure and transformations of myosin and other ATPases in solution. Electric-optical and hydrodynamic properties of DNA are being studied, especially in the high field region (greater than 10 to the 4th power v/cm) where structural transformations occur. An on-line computer interface has been designed for rapid E-O relaxation data analysis. Computer programs are being completed and tested. Cell design and optics are being improved by incorporating a laser source.